Substrate adsorption method, substrate holding apparatus, substrate polishing apparatus, elastic film, substrate adsorption determination method for substrate holding apparatus, and pressure control method for substrate holding apparatus

ABSTRACT

A method includes: vacuuming at least one area among a plurality of areas formed concentrically between a top face of the elastic film and the top ring body under a state where a bottom face of the substrate is supported by a support member and a top face of the substrate contacts a bottom face of the elastic film; measuring a flow volume of gas in an area located outside one or more areas to be vacuumed; determining whether the substrate is adsorbed to the top ring based on the flow volume of the gas; and after it is determined that the substrate is adsorbed to the top ring, separating the elastic film to which the substrate is adsorbed from the support member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Priority PatentApplications JP 2015-161187 filed on Aug. 18, 2015, JP 2016-097291 filedon May 13, 2016, and JP 2016-134881 filed on Jul. 7, 2016, the entirecontents of which are incorporated herein by reference.

FIELD

The present disclosure relates to a substrate adsorption method, asubstrate holding apparatus, a substrate polishing apparatus, an elasticfilm, a substrate adsorption determination method for a substrateholding apparatus, and a pressure control method for a substrate holdingapparatus.

BACKGROUND AND SUMMARY

A substrate polishing apparatus that polishes a substrate such as asemiconductor wafer polishes a substrate held by a top ring by pressingthe substrate to a polishing table. To transfer the substrate from atransport mechanism to the top ring, the substrate supported by thetransport mechanism is firstly caused to come into contact with amembrane that is provided on a lower surface of the top ring andconcentrically divided into a plurality of areas. Then, the substrate isvacuum drawn from a hole formed in the membrane, so that the substrateis adsorbed to the membrane.

It is desired to provide a substrate adsorption method, a substrateholding apparatus, a substrate polishing apparatus, an elastic film, asubstrate adsorption determination method for a substrate holdingapparatus, and a pressure control method for a substrate holdingapparatus, for appropriately handling a substrate.

According to one embodiment, a method to adsorb a substrate to a topring comprising a top ring body and an elastic film under the top ringbody, the method comprises: vacuuming at least one area among aplurality of areas formed concentrically between a top face of theelastic film and the top ring body under a state where a bottom face ofthe substrate is supported by a support member and atop face of thesubstrate contacts a bottom face of the elastic film; measuring a flowvolume of gas in an area located outside one or more areas to bevacuumed; determining whether the substrate is adsorbed to the top ringbased on the flow volume of the gas; and after it is determined that thesubstrate is adsorbed to the top ring, separating the elastic film towhich the substrate is adsorbed from the support member.

According to another embodiment, a substrate holding apparatuscomprises: a top ring body; an elastic film under the top ring body, aplurality of areas being concentrically formed between a top face of theelastic film and the top ring body; a pressure controller configured tovacuum at least one area among the plurality of areas under a statewhere a top face of a substrate whose bottom face is supported by asupport member contacts a bottom face of the elastic film; a flow meterconfigured to measure a flow volume of gas in an area located outsideone or more areas to be vacuumed; and a determiner configured todetermine whether the substrate is adsorbed to the top ring based on theflow volume of the gas.

According to another embodiment, a substrate holding apparatuscomprising: a top ring body; an elastic film comprising a first face anda second face opposite the first face, a plurality of areas being formedbetween the first face and the top ring body, the second face beingcapable of holding a substrate; a first line communicating with a firstarea among the plurality of areas and capable of pressuring the firstarea; a second line communicating with the first area and capable ofexhausting the first area; a measurement instrument whose measurementvalue varies based on a flow volume of the first area; a third linecommunicating with a second area among the plurality of areas anddifferent from the first area, the third line being capable ofpressuring or depressurizing the second area.

According to another embodiment, a substrate adsorption determinationmethod for a substrate holding apparatus, the method comprising:depressurizing a second area formed between a top ring body and a firstface of an elastic film in the substrate holding apparatus, pressuring afirst area formed between the top ring body and the first face of theelastic film different from the second area and making a fluid through asecond line communicating with the first area; and determining whetherthe substrate is adsorbed to a second face of the elastic film oppositethe first face based on a measurement value varying according to a flowvolume of the first area.

According to another embodiment, a pressure control method for asubstrate holding apparatus, the method comprising: pressurizing a firstarea formed between a top ring body and a first face of an elastic filmin the substrate holding apparatus, and making a fluid through a secondline communicating with the first area; and controlling a second areaformed between the top ring body and the first face of the elastic filmdifferent from the first area based on a measurement value varyingaccording to a flow volume of the first area.

According to another embodiment, an elastic film used with a top ringbody provided with a first hole at an outside of a first portion and asecond hole at an inside of the first portion to configure a substrateholding apparatus, the elastic film comprising: a first face providedwith a second portion capable of being engaged with the first portion, aplurality of areas being formed between the first face and the top ringbody; and a second face opposite the first face, the second face beingcapable of holding a substrate.

According to another embodiment, a substrate holding apparatuscomprising: a top ring body provided with a first hole at an outside ofa first portion and a second hole at an inside of the first portion; anelastic film comprising: a first face provided with a second portioncapable of being engaged with the first portion, a plurality of areasbeing formed between the first face and the top ring body; and a secondface opposite the first face, the second face being capable of holding asubstrate; a first line being capable of pressuring a first area throughthe first hole positioned at the first area among the plurality ofareas; a second line capable of depressurizing the first are through thesecond hole positioned at the first area; a measurement instrument whosemeasurement value varies based on a flow volume of the first area; and athird line communicating with a second area among the plurality of areasand different from the first area, the third line being capable ofpressuring or depressurizing the second area.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic top view of a substrate processing apparatusincluding a substrate polishing apparatus 300;

FIG. 2A is a schematic perspective view of the substrate polishingapparatus 300;

FIG. 2B is a cross-sectional view of the substrate polishing apparatus300;

FIG. 3A is a diagram for explaining transfer of a substrate from atransport mechanism 600 b to a top ring 1;

FIG. 3B is a diagram for explaining transfer of the substrate from thetransport mechanism 600 b to the top ring 1;

FIG. 3C is a diagram for explaining transfer of the substrate from thetransport mechanism 600 b to the top ring 1;

FIG. 4 is a diagram for explaining transfer of the substrate from thetransport mechanism 600 b to the top ring 1;

FIG. 5 is a cross-sectional view schematically showing a structure ofthe top ring 1;

FIG. 6 is a diagram showing an example of an internal configuration of apressure control means 15;

FIG. 7A is a flowchart showing a transfer procedure of a substrate Wincluding an adsorption completion determination of the substrate W;

FIG. 7B is a flowchart showing a transfer procedure of the substrate Wincluding the adsorption completion determination of the substrate W;

FIG. 8A is a view of a membrane 13 and the substrate W before beingvacuum drawn as seen from side;

FIG. 8B is a view of the membrane 13 and the substrate W after beingvacuum drawn as seen from side;

FIG. 9 is a diagram schematically showing measurement results of apressure gauge 164 b and a flow meter 165 a after starting vacuuming;

FIG. 10 is a diagram showing another example of the internalconfiguration of the pressure control means 15;

FIG. 11 is a diagram showing further another example of the internalconfiguration of the pressure control means 15;

FIG. 12 is a flowchart showing an adsorption procedure of the substrateW including the adsorption completion determination of the substrate W;

FIG. 13 is a schematic cross-sectional view of the substrate polishingapparatus 300;

FIG. 14A is a cross-sectional view schematically showing a structure ofthe top ring 1 in a third embodiment;

FIG. 14B is a modified example of FIG. 14A;

FIG. 15 is a cross-sectional view showing details of a top ring body 11and a membrane 13 in the top ring 1;

FIG. 16 is a cross-sectional view taken along line A-A′ in FIG. 15;

FIG. 17 is a diagram for explaining an operation of each valve in thetop ring 1;

FIG. 18 is a flowchart showing a procedure of substrate adsorptiondetermination;

FIG. 19 is a diagram schematically showing cross sections of themembrane 13 and the top ring body 11 when adsorption fails;

FIG. 20 is a diagram schematically showing cross sections of thesubstrate W, the membrane 13, and the top ring body 11 when adsorptionsucceeds;

FIG. 21 is a diagram schematically showing flow volumes measured by aflow meter FS after starting adsorption;

FIG. 22 is a cross-sectional view schematically showing a structure ofthe top ring 1 in a fourth embodiment;

FIG. 23 is a diagram schematically showing cross sections of themembrane 13 and the top ring body 11 when adsorption fails;

FIG. 24 is a diagram schematically showing cross sections of thesubstrate W, the membrane 13, and the top ring body 11 when adsorptionsucceeds;

FIG. 25 is a cross-sectional view schematically showing a structure ofthe top ring 1 which is a modified example of FIG. 22;

FIG. 26 is a diagram schematically showing cross sections of themembrane 13 and the top ring body 11 when adsorption fails;

FIG. 27 is a diagram schematically showing cross sections of thesubstrate W, the membrane 13, and the top ring body 11 when adsorptionsucceeds;

FIG. 28A is a diagram for explaining in detail transfer of a substratefrom the top ring 1 to the transport mechanism 600 b;

FIG. 28B is a diagram for explaining in detail transfer of the substratefrom the top ring 1 to the transport mechanism 600 b;

FIG. 28C is a diagram for explaining in detail transfer of the substratefrom the top ring 1 to the transport mechanism 600 b;

FIG. 29 is a diagram for explaining in detail transfer of the substratefrom the top ring 1 to the transport mechanism 600 b;

FIG. 30 is a diagram schematically showing a state before startingrelease;

FIG. 31 is a diagram schematically showing a state after startingrelease;

FIG. 32 is a diagram schematically showing a state after startingrelease following FIG. 33;

FIG. 33 is a diagram schematically showing a state after startingrelease following FIG. 32;

FIG. 34 is a cross-sectional view schematically showing a structure ofthe top ring 1 in a fifth embodiment;

FIG. 35 is a flowchart showing an operation of the top ring 1 duringrelease;

FIG. 36 is a diagram schematically showing a flow volume measured by theflow meter FS during release;

FIG. 37 is a side view schematically showing an operation in which thesubstrate W is released from the top ring 1 and transferred to a pusher160;

FIG. 38 is a cross-sectional view of the top ring body 11 and themembrane 13 near an area 131;

FIG. 39 is a view of the membrane 13 near an area 131 as seen fromabove;

FIG. 40 is a view of the top ring body 11 near an area 131 as seen frombelow;

FIG. 41 is a diagram showing a configuration example of a pressurecontrol apparatus 7 in a case in which substrate adsorptiondetermination is performed by using the flow meter FS;

FIG. 42 is a diagram for explaining pressurization during the adsorptiondetermination;

FIG. 43 is a diagram for explaining pressurization while polishing asubstrate;

FIG. 44 is a diagram schematically showing cross sections of thesubstrate W, the membrane 13, and the top ring body 11 when adsorptionsucceeds; and

FIG. 45 is a cross-sectional view of the top ring body 11 and themembrane 13 which are a modified example of FIG. 38.

DESCRIPTION

According to one embodiment, a method to adsorb a substrate to a topring comprising a top ring body and an elastic film under the top ringbody is provided. The method comprises: vacuuming at least one areaamong a plurality of areas formed concentrically between a top face ofthe elastic film and the top ring body under a state where a bottom faceof the substrate is supported by a support member and atop face of thesubstrate contacts a bottom face of the elastic film; measuring a flowvolume of gas in an area located outside one or more areas to bevacuumed; determining whether the substrate is adsorbed to the top ringbased on the flow volume of the gas; and after it is determined that thesubstrate is adsorbed to the top ring, separating the elastic film towhich the substrate is adsorbed from the support member.

If a certain area is vacuum drawn, when the substrate is adsorbed to theelastic film, a volume of an area located outside the vacuuming targetarea becomes small. This is detected based on the flow volume of the gasin the area located outside the vacuuming target area. Therefore, it ispossible to determine whether the substrate is adsorbed to the elasticfilm.

It is preferable that the method further comprises measuring pressure ofat least one area among the one or more areas to be vacuumed aftervacuuming at least one area among the plurality of areas, whereinwhether the substrate is absorbed is determined taking intoconsideration the flow volume of the gas and the pressure of at leastone area among the one or more areas to be vacuumed.

The accuracy of the determination is further improved by considering thepressure (the degree of vacuum) in the vacuuming target area.

It is preferable that the method further comprises: pressuring at leastone area among the plurality of areas; and contacting the top face ofthe substrate with the bottom face of the elastic film, whereinvacuuming at least one area among the plurality of areas is performedthereafter.

This is because even when the elastic film and the top ring body areclosely attached to each other, this state is released by pressurizingin advance and it is possible to increase the contact area between theelastic film and the substrate.

It is more preferable that upon pressuring at least one area, at leastone of the areas to be vacuumed is pressured.

When the vacuuming target area is the center of the elastic film, thecenter of the elastic film has a downward convex shape, so that it ispossible to cause the central portion of the substrate to reliably comeinto contact with the elastic film.

It is preferable that an area located outside the areas to be vacuumedis not pressured when the top face of the substrate contacts the bottomface of the elastic film.

This is because when an area located outside the vacuuming target areais pressurized, the substrate is curved like a bow and a load is appliedto the substrate.

The support member may be a transfer mechanism configured to transferthe substrate to the top ring.

In this case, it is possible to reliably transfer the substrate from thetransport mechanism to the top ring.

The support member may be a polishing table configured to polish thesubstrate holed by the top ring.

In this case, it is possible to cause the substrate to be reliablyadsorbed to the top ring from the polishing table after the polishing ofthe substrate.

According to another embodiment, a substrate holding apparatus isprovided. The apparatus comprises: a top ring body; an elastic filmunder the top ring body, a plurality of areas being concentricallyformed between a top face of the elastic film and the top ring body; apressure controller configured to vacuum at least one area among theplurality of areas under a state where a top face of a substrate whosebottom face is supported by a support member contacts a bottom face ofthe elastic film; a flow meter configured to measure a flow volume ofgas in an area located outside one or more areas to be vacuumed; and adeterminer configured to determine whether the substrate is adsorbed tothe top ring based on the flow volume of the gas.

By this aspect, it is possible to accurately determine whether thesubstrate is adsorbed to the elastic film.

It is preferable that a flow path on which the flow meter is provided isconnected to the area located outside the one or more areas to bevacuumed, and the flow path is not branched between said area and theflow meter.

By doing so, it is possible for the flow meter to correctly measure theflow volume in the area.

It is preferable that no holes are formed on the elastic film at aposition where the plurality of areas are formed.

There is no hole, so that it is possible to prevent powder dustgenerated inside the top ring from contaminating the substrate and it ispossible to prevent gas from leaking from between the elastic film andthe adsorbed substrate.

According to another embodiment, a substrate polishing apparatus isprovided. The apparatus comprises: the substrate holding apparatusaccording to claim 8; a transfer mechanism configured to transfer thesubstrate to the substrate holding apparatus; and a polishing tableconfigured to polish the substrate held by the substrate holdingapparatus.

According to another embodiment, a substrate holding apparatus isprovided. The apparatus comprises: a top ring body; an elastic filmcomprising a first face and a second face opposite the first face, aplurality of areas being formed between the first face and the top ringbody, the second face being capable of holding a substrate; a first linecommunicating with a first area among the plurality of areas and capableof pressuring the first area; a second line communicating with the firstarea and capable of exhausting the first area; a measurement instrumentwhose measurement value varies based on a flow volume of the first area;a third line communicating with a second area among the plurality ofareas and different from the first area, the third line being capable ofpressuring or depressurizing the second area.

It is possible to appropriately handle the substrate by using the flowvolume measured by the flow meter.

The measurement instrument may be a flow meter capable of measuring aflow volume of the second line. The measurement instrument may be apressure gauge capable of measuring a pressure of the first line of thesecond line.

It is preferable that the apparatus further comprises a determinerconfigured to determine whether the substrate is adsorbed to the secondface based on the measurement value.

The flow volume measured by the flow meter corresponds to a gap betweenthe top ring body and the first surface of the elastic film. When thesubstrate is adsorbed, the gap becomes small and the flow volumedecreases, so that it is possible to accurately determine whether thesubstrate is adsorbed.

It is preferable that the apparatus further comprises a controllerconfigured to, when the substrate is adsorbed to the second face,depressurize the second area through the third line and pressure thefirst area through the first line and make a fluid through the secondline; wherein the determiner determines whether the substrate isadsorbed to the second face based on the measurement value when thesubstrate is adsorbed to the second face.

The flow volume is measured in a state in which the first area is openedto the atmosphere, so that it is possible to prevent the elastic filmfrom applying stress to the substrate.

It is preferable that the determiner determines whether the substrate isadsorbed to the second face based on the measurement value measured bythe measurement instrument after a first time from a start ofdepressurizing the second area.

Thereby, it is possible to perform accurate determination.

It is preferable that the apparatus further comprises a controllerconfigured to control a pressure of the second area through the thirdline based on the measurement value.

The flow volume measured by the flow meter corresponds to the gapbetween the top ring body and the first surface of the elastic film. Thegap corresponds to a swell of the elastic film. Therefore, it ispossible to control the swell of the elastic film by monitoring the flowvolume.

It is preferable that the controller controls the pressure of the secondarea so that the measurement value falls within a first range.

Thereby, it is possible to maintain the swell of the elastic film withina predetermined range.

It is preferable that the controller, when the substrate held by thesecond face is released, pressures the first area through the first lineand make a fluid into the first area through the second line, andcontrols the second area through the third line based on the measurementvalue.

It is preferable that the controller controls the pressure of the secondarea so that a fluid is injected to a first position from a releasenozzle.

It is more preferable that the first position is between the second faceand the hold substrate.

Thereby, it is possible to continue jetting fluid from the releasenozzle into between the second surface of the elastic film and thesubstrate, so that the substrate can be effectively released.

It is preferable that no holes are formed on the elastic film.

It is preferable that the second area is not adjacent to the first area.

Thereby, when the substrate is not adsorbed to the second area, the gapbetween the first area and the first surface is maintained.

It is preferable that the apparatus comprises a retainer ring at anouter circumference of the elastic film.

The retainer ring may comprise an inner ring and an outer ring outsidethe inner ring.

According to another embodiment, a substrate polishing apparatus isprovided. The apparatus comprises: the substrate holding apparatusaccording to claim 12; and a polishing table configured to polish thesubstrate held by the substrate holding apparatus.

According to another embodiment, a substrate adsorption determinationmethod for a substrate holding apparatus is provided. The methodcomprises: depressurizing a second area formed between a top ring bodyand a first face of an elastic film in the substrate holding apparatus,pressuring a first area formed between the top ring body and the firstface of the elastic film different from the second area and making afluid through a second line communicating with the first area; anddetermining whether the substrate is adsorbed to a second face of theelastic film opposite the first face based on a measurement valuevarying according to a flow volume of the first area.

According to another embodiment, a pressure control method for asubstrate holding apparatus is provided. The method comprises:pressurizing a first area formed between a top ring body and a firstface of an elastic film in the substrate holding apparatus, and making afluid through a second line communicating with the first area; andcontrolling a second area formed between the top ring body and the firstface of the elastic film different from the first area based on ameasurement value varying according to a flow volume of the first area.

According to another embodiment, an elastic film used with a top ringbody provided with a first hole at an outside of a first portion and asecond hole at an inside of the first portion to configure a substrateholding apparatus is provided. The elastic film comprises: a first faceprovided with a second portion capable of being engaged with the firstportion, a plurality of areas being formed between the first face andthe top ring body; and a second face opposite the first face, the secondface being capable of holding a substrate.

The first portion and the second portion engage with each other, so thata difference between a case in which the substrate is held and a case inwhich the substrate is not held becomes large. Therefore, it is possibleto accurately perform the substrate adsorption determination.

The first portion may be a concave portion and the second portion may bea convex portion, or the first portion may be a convex portion and thesecond portion may be a concave portion.

According to another embodiment, a substrate holding apparatus isprovided. The apparatus comprises: a top ring body provided with a firsthole at an outside of a first portion and a second hole at an inside ofthe first portion; an elastic film comprising: a first face providedwith a second portion capable of being engaged with the first portion, aplurality of areas being formed between the first face and the top ringbody; and a second face opposite the first face, the second face beingcapable of holding a substrate; a first line being capable of pressuringa first area through the first hole positioned at the first area amongthe plurality of areas; a second line capable of depressurizing thefirst are through the second hole positioned at the first area; ameasurement instrument whose measurement value varies based on a flowvolume of the first area; and a third line communicating with a secondarea among the plurality of areas and different from the first area, thethird line being capable of pressuring or depressurizing the secondarea.

It is preferable that a radially spreading groove is provided at aportion of the top ring body corresponding to the first area.

It is preferable that the substrate holding apparatus furthercomprising: a bypass line configured to connect the first line with thesecond line; and a valve provided on the bypass line.

It is possible to pressurize the first area from both the first line andthe second line by opening the valve on the bypass line. Thereby, it ispossible to quickly pressurize the entire first area by the samepressure even when the second portion engages with the first portionwhen pressurizing the first area.

Hereinafter, embodiments will be specifically described with referenceto the drawings.

First Embodiment

As described in BACKGROUND AND SUMMARY, the substrate is vacuum drawnfrom a hole formed in the membrane, so that the substrate is adsorbed tothe membrane. If the hole formed in the membrane is large, powder dustgenerated inside the top ring may go through the hole and contaminatethe substrate, or gas may leak from between the membrane and thevacuum-adsorbed substrate. Therefore, in recent years, the hole formedin the membrane tends to be small as much as possible. Further, thesubstrate may be adsorbed by deforming the surface shape of the membraneby vacuuming without using the hole.

When the hole is small or no hole is made, a force of adsorbing thesubstrate becomes small. If the top ring is moved before the substrateis sufficiently adsorbed to the top ring, the substrate may fall.Therefore, it is necessary to detect that the substrate is adsorbed tothe top ring and the transfer from the transport mechanism is completed.Normally, the vacuum pressure of the area that is vacuum drawn ismeasured, and it is determined that the transfer of the substrate iscompleted when the vacuum pressure reaches a predetermined thresholdvalue.

However, even when the determination is performed based on the vacuumpressure of the area that is vacuum drawn, a sufficient adhesive forceis not necessarily generated between the substrate and the membrane.Therefore, for safety's sake, it is required to set a severe thresholdvalue or move the top ring after waiting a predetermined time when thethreshold value is reached. Doing so makes the transfer time of thesubstrate longer than the time originally required, so that there is aproblem that the throughput decreases.

The first and the second embodiments have been made in view of the aboveproblem and an object of the first and the second embodiments are toprovide a substrate adsorption method that can cause the substrate to bereliably adsorbed to the top ring, a substrate holding apparatus thatreliably adsorbs the substrate, and a substrate polishing apparatusincluding such a substrate holding apparatus.

FIG. 1 is a schematic top view of a substrate processing apparatusincluding a substrate polishing apparatus 300. The substrate processingapparatus processes various substrates in a manufacturing process andthe like of a semiconductor wafer having a diameter of 300 mm or 450 mm,a flat panel, an image sensor of a CMOS (Complementary Metal OxideSemiconductor), a CCD (Charge Coupled Device), and the like, and amagnetic film in MRAM (Magnetoresistive Random Access Memory).

The substrate processing apparatus includes a substantially rectangularhousing 100, a load port 200 on which a substrate cassette that stocksmany substrates is mounted, one or a plurality of (four in the aspectshown in FIG. 1) substrate polishing apparatuses 300, one or a pluralityof (two in the aspect shown in FIG. 1) substrate cleaning apparatuses400, a substrate drying apparatus 500, transport mechanisms 600 a to 600d, and a controller 700.

The load port 200 is arranged adjacent to the housing 100. It ispossible to mount an open cassette, an SMIF (Standard MechanicalInterface) pod, or a FOUP (Front Opening Unified Pod) on the load port200. The SMIF pod or the FOUP is a closed container that can maintain anenvironment independent from the external space by housing the substratecassette inside thereof and covering the substrate cassette with aconfining wall.

The substrate polishing apparatuses 300 that polish a substrate, thesubstrate cleaning apparatuses 400 that clean the substrate that hasbeen polished, and the substrate drying apparatus 500 that dries thesubstrate that has been cleaned are housed in the housing 100. Thesubstrate polishing apparatuses 300 are arranged along a longitudinaldirection of the substrate processing apparatus. The substrate cleaningapparatuses 400 and the substrate drying apparatus 500 are also arrangedalong the longitudinal direction of the substrate processing apparatus.

The transport mechanism 600 a is arranged in an area surrounded by theload port 200, the substrate polishing apparatus 300 located facing theload port 200, and the substrate drying apparatus 500. The transportmechanism 600 b is arranged in parallel with the substrate polishingapparatuses 300 and also in parallel with the substrate cleaningapparatuses 400 and the substrate drying apparatus 500.

The transport mechanism 600 a receives a substrate before being polishedfrom the load port 200 and transfers the substrate to the transportmechanism 600 b, and also receives a substrate that has been dried fromthe substrate drying apparatus 500.

The transport mechanism 600 b is, for example, a linear transporter andtransfers the substrate before being polished which is received from thetransport mechanism 600 a to the substrate polishing apparatuses 300. Asdescribed later, the top ring (not shown in FIG. 1) in the substratepolishing apparatus 300 receives the substrate from the transportmechanism 600 b by vacuum adsorption. The substrate polishing apparatus300 releases the substrate that has been polished to the transportmechanism 600 b and the substrate is transferred to the substratecleaning apparatus 400.

Further, the transport mechanism 600 c that performs transfer of thesubstrate between the two substrate cleaning apparatuses 400 is arrangedbetween these substrate cleaning apparatuses 400. Further, the transportmechanism 600 d that performs transfer of the substrate between thesesubstrate cleaning apparatuses 400 and the substrate drying apparatus500 is arranged between these substrate cleaning apparatuses 400 and thesubstrate drying apparatus 500.

The controller 700 controls operation of each device in the substrateprocessing apparatus. The controller 700 may be arranged inside thehousing 100, may be arranged outside the housing 100, or may be providedfor each of the substrate polishing apparatuses 300, the substratecleaning apparatuses 400, and the substrate drying apparatus 500.

FIGS. 2A and 2B are a schematic perspective view and a cross-sectionalview, respectively, of the substrate polishing apparatus 300. Thesubstrate polishing apparatus 300 includes a top ring 1, a top ringshaft 2 where the top ring 1 is connected to a lower part of the topring shaft 2, a polishing table 3 having a polishing surface 3 a, anozzle 4 that supplies polishing liquid on the polishing table 3, a topring head 5, and a support shaft 6.

The top ring 1 holds a substrate W and presses the lower surface of thesubstrate W onto the polishing surface 3 a. As shown in FIG. 2B, the topring 1 includes a top ring body (a carrier) 11, a ring-shaped retainerring 12, a flexible membrane 13 (an elastic film) that is provided belowthe top ring body 11 and inside the retainer ring 12, and an air bag 14provided between the top ring body 11 and the retainer ring 12. Theupper surface of the substrate W is held by the top ring 1 bydepressurizing a space between the top ring body 11 and the membrane 13.The circumferential edge of the substrate W is surrounded by theretainer ring 12, so that the substrate W does not run away from the topring 1 during polishing.

The top ring shaft 2 is connected to the center of the upper surface ofthe top ring 1. An elevating mechanism not shown in the drawings movesup and down the top ring shaft 2, so that the lower surface of thesubstrate W held by the top ring 1 is attached to and detached from thepolishing surface 3 a. Further, a motor not shown in the drawingsrotates the top ring shaft 2, so that the top ring 1 rotates and thesubstrate W held by the top ring 1 also rotates.

The polishing surface 3 a is provided on the upper surface of thepolishing table 3. The lower surface of the polishing table 3 isconnected to a rotating shaft, so that the polishing table 3 isrotatable. The polishing liquid is supplied from the nozzle 4, and thesubstrate W and the polishing table 3 rotate in a state in which thelower surface of the substrate W is in contact with the polishingsurface 3 a, so that the substrate W is polished.

The top ring shaft 2 is connected to one end of the top ring head 5 andthe support shaft 6 is connected to the other end of the top ring head5. When a motor not shown in the drawings rotates the support shaft 6,the top ring head 5 swings, so that the top ring 1 moves back and forthbetween a position on the polishing surface 3 a and a substrate transferposition (not shown in the drawings).

The substrate polishing apparatus 300 operates as described below.First, the top ring head 5 swings, so that the top ring 1 moves to thesubstrate transfer position and the substrate W is transferred from atransport mechanism (not shown in the drawings) to the top ring 1.Thereby, the upper surface of the substrate W is held by the top ring 1.Details of this point will be described later.

Subsequently, the top ring head 5 swings in the opposite direction, sothat the top ring 1 moves to a position on the polishing surface 3 a.Further, the top ring shaft 2 comes down to cause to the lower surfaceof the substrate W to come into contact with the polishing surface 3 a.Then, the top ring 1 and the polishing table 3 rotate while thepolishing liquid is being supplied from the nozzle 4 to the polishingsurface 3 a, so that the substrate W is polished. After the polishing,the top ring 1 holds the substrate W again and the top ring head 5swings, so that the top ring 1 moves to the substrate transfer position.

Subsequently, the transfer of the substrate from the transport mechanism600 b to the top ring 1 at the substrate transfer position will bedescribed.

FIGS. 3A to 3C and 4 are diagrams for explaining the transfer of thesubstrate from the transport mechanism 600 b to the top ring 1. FIGS. 3Ato 3C are diagrams of the transport mechanism 600 b and the top ring 1as seen from side and FIG. 4 is a diagram of these as seen from above.

As shown in FIGS. 3A to 3C, the substrate W is mounted on the transportmechanism 600 b (more specifically, on a hand 601 of the transportmechanism 600 b). As shown in FIG. 4, the hand 601 supports parts ofouter circumference of the lower surface of the substrate W. Thetransport mechanism 600 b is moved upward and downward by an elevatingmechanism not shown in the drawings.

A retainer ring station 800 is used for the transfer of the substrate W.As shown in FIG. 3A, the retainer ring station 800 has a push-up pin 801that pushes up the retainer ring 12 of the top ring 1. Although theretainer ring station 800 may have a release nozzle, the release nozzleis not shown in the drawings. As shown in FIG. 4, the push-up pin 801and the hand 601 are arranged not to be in contact with each other.

The transport mechanism 600 b and the top ring 1 operate as describedbelow and the substrate W is transferred from the transport mechanism600 b to the top ring 1. First, as shown in FIG. 3A, the top ring 1moves downward and the transport mechanism 600 b moves upward. The topring 1 moves downward, so that the push-up pin 801 pushes up theretainer ring 12. Further, the substrate W comes close to the membrane13.

When the transport mechanism 600 b moves further upward, as shown inFIG. 3B, the upper surface of the substrate W comes into contact withthe lower surface of the membrane 13. In this state, the substrate W isadsorbed to the membrane 13 in a manner as described below. At thistime, a determination is made whether the substrate W is reliablyadsorbed to the membrane 13, in other words, a determination is madewhether the transfer of the substrate W has been completed. When it isdetermined that the transfer of the substrate W has been completed, asshown in FIG. 3C, the top ring 1 moves upward and the transportmechanism 600 b moves downward.

Next, the adsorption of the substrate W and the determination of thecompletion of the adsorption of the substrate W will be described.

FIG. 5 is a cross-sectional view schematically showing a structure ofthe top ring 1. Circumferential walls 13 a to 13 h extending upwardtoward the top ring body 11 are formed on the membrane 13. By thesecircumferential walls 13 a to 13 h, concentric areas 131 to 138, whichare divided by the circumferential walls 13 a to 13 h, are formedbetween the upper surface of the membrane 13 and the lower surface ofthe top ring body 11.

A hole may be formed at positions where the areas 131 to 138 in themembrane 13 are formed. However, it is desirable that the hole is assmall as possible. It is further desirable that no hole is formed in themembrane 13. In the present embodiment, even in such a case in which theadsorption force is not strong, it is possible to prevent the substrateW from falling by accurately determining that the substrate W isadsorbed to the top ring 1.

Flow paths 141 to 148 that penetrate the top ring body 11 andcommunicate with the areas 131 to 138, respectively, are formed. Aretainer chamber 139 made of an elastic film is provided directly on theretainer ring 12 and a flow path 149 that connects to the retainerchamber 139 is formed in the same manner. The flow paths 141 to 149 areconnected to a pressure control means 15, and the pressures in the areas131 to 138 and the retainer chamber 139 are controlled.

In the present embodiment, as a specific example, it is assumed that theareas 131 to 134, which are located near the center, can be pressurizedand can be vacuum drawn through the flow paths 141 to 144, respectively,and the areas 135 to 138 and the retainer chamber 139, which are locatedouter, can be opened to the atmosphere through the flow paths 145 to149, respectively.

FIG. 6 is a diagram showing an example of an internal configuration ofthe pressure control means 15. The configurations related to the flowpaths 141 to 144 are the same, so that only the flow path 141 is shownin FIG. 6. In the same manner, the configurations related to the flowpaths 145 to 149 are the same, so that only the flow path 145 is shownin FIG. 6.

The flow path 141 is provided with a flow meter 161 a and the flow meter161 a measures a flow volume of gas flowing into the area 131 (orflowing out from the area 131). The flow path 141 is provided with apressure gauge 161 b and the pressure gauge 161 b measures the pressurein the area 131.

The flow path 141 branches at a position beyond the flow meter 161 a andthe pressure gauge 161 b, and one branch is connected to a fluid supplysource 18 through a valve 171 a and the other branch is connected to avacuum source 19 through a valve 171 b. The area 131 can be pressurizedby opening the valve 171 a and supplying gas such as nitrogen from thefluid supply source 18. The area 131 can be vacuum drawn (depressurized)by opening the valve 171 b and performing vacuuming by the vacuum source19.

Here, it is desirable that the path between the area 131, the flow meter161 a, and the pressure gauge 161 b is a single pipe and does notbranch. This is because almost all of the gas that goes out of the area131/enters the area 131 passes through the flow meter 161 a and thepressure gauge 161 b, so that the flow meter 161 a and the pressuregauge 161 b can measure the gas flow volume and the pressure of the area131, respectively, regardless of an open or closed state of the valves171 a and 171 b.

Of course, when there is no leak or when it is possible to divide theflow path of the gas by providing a valve at an appropriate position,there may be a branch between the area 131, the flow meter 161 a, andthe pressure gauge 161 b.

Although not shown in the drawings, the flow meters and the pressuregauges provided in the flow paths 142 to 144 are referred to as flowmeters 162 a to 164 a and pressure gauges 162 b to 164 b, respectively.

On the other hand, the flow path 145 is provided with the flow meter 165a and the pressure gauge 165 b. Beyond the flow meter 165 a and thepressure gauge 165 b, the flow path 145 communicates with atmospherethrough a valve 175. It is possible to open the area 135 to theatmosphere by opening the valve 175. Although not shown in the drawings,the flow meters and the pressure gauges provided in the flow paths 146to 149 are referred to as flow meters 166 a to 169 a and pressure gauges166 b to 169 b, respectively.

FIG. 6 is just an example, and various modifications are possible. Forexample, the flow paths 145 to 149 may be connected to the fluid supplysource 18 and/or the vacuum source 19 through a valve by providing abranch or may be caused to have an atmospheric pressure by supplyingfluid instead of communicating with the atmosphere. The flow paths 141to 144 may be communicated with the atmosphere through a valve byfurther providing a branch. In either case, it is preferable that thereis no branch between the flow meter, the pressure gauge, and an area.

Referring back to FIG. 5, the top ring 1 includes a determination means1A that is connected to the pressure control means 15. As describedlater, the determination means 1A determines whether the substrate W isadsorbed to the membrane 13 of the top ring 1, in other words, whetherthe transfer of the substrate W from the transport mechanism 600 b tothe top ring 1 has been completed, based on necessary measurementresults of the flow meters 161 a to 169 a and the pressure gauges 161 bto 169 b.

FIG. 7A is a flowchart showing a transfer procedure of the substrate Wincluding an adsorption completion determination of the substrate W.

First, the upper surface of the substrate W and the lower surface of themembrane 13 are caused to come into contact with each other by using thetransport mechanism 600 b as a support member. Specifically, asdescribed by using FIGS. 3A to 3C, the transport mechanism 600 b thatsupports the lower surface of the substrate W moves upward and the topring 1 moves downward (step S1), so that the upper surface of thesubstrate W and the lower surface of the membrane 13 come into contactwith each other (step S2).

Subsequently, the pressure control means 15 perform vacuuming on areasnear the center among the areas 131 to 138 formed between the top ringbody 11 and the membrane 13 (step S3).

By concerning that the greater the number of areas to be vacuum drawnis, the higher the adsorption force is, the appropriate number of areasshould be vacuum drawn. For example, when a high adsorption force is notrequired, only the area 131 should be vacuum drawn, and when a highadsorption force is required, the areas 131 to 134 should be vacuumdrawn. Hereinafter, it is assumed that the areas 131 to 134 are vacuumdrawn. In this case, the vacuum source 19 should be operated in a statein which only the valves 171 b to 174 b are opened. In the membrane 13in the area 134, a plurality of small holes described above may beevenly arranged in a predetermined concentric fashion.

FIGS. 8A and 8B are views of the membrane 13 and the substrate W beforeand after being vacuum drawn, respectively, as seen from side. As shownin FIG. 8A, before being vacuum drawn, the membrane 13 is substantiallyflat and the pressure in the areas 131 to 138 is the atmosphericpressure. When the areas 131 to 134 are vacuum drawn, as shown in FIG.8B, the membrane 13 is slightly deformed, a central portion of thesubstrate W is adsorbed to the membrane 13 by a sucker effect, and theouter circumferential portion of the substrate W and the outercircumferential portion of the membrane 13 are closely attached to eachother to generate a sealing effect, so that the substrate W is stronglyadsorbed to the membrane 13.

At this time, the pressure in the areas 131 to 134 that are vacuum drawndecreases and becomes close to vacuum. The membrane 13 is drawn towardthe top ring body 11, so that the volumes of the areas 135 to 138 (inparticular, the area 135) decrease. Therefore, the gases in the areas135 to 138 flow out from the flow paths 145 to 148.

It is possible to detect that the substrate W is adsorbed to themembrane 13 from a fact that the volumes of the areas 135 to 138decrease. The fact that the volumes of the areas 135 to 138 decrease canbe detected from the flow volumes of the flow meters 165 a to 168 a.

It is desirable that the valves 175 to 178 for the areas 135 to 138 thatare not vacuum drawn are opened and the pressure in the areas 135 to 138is set to the atmospheric pressure without being pressurized. This isbecause although the areas 135 to 138 may be pressurized, doing so makesthe membrane 13 bend largely in an arch shape and accordingly thesubstrate W is also bent and a load is applied to the substrate W.

Referring back to FIG. 7A. When the vacuuming of the areas 131 to 134 isstarted, the pressure gauges 161 b to 164 b provided to thecorresponding flow paths 141 to 144 measure the pressure of the areas131 to 134, respectively (step S4), and the results of the measurementsare transmitted to the determination means 1A.

When the vacuuming of the areas 131 to 134 is started, the flow meters165 a to 168 a provided to the flow paths 145 to 148 corresponding tothe areas 135 to 138 located outside the areas 131 to 134 measure theflow volumes, respectively (step S5), and the results of themeasurements are transmitted to the determination means 1A. As describedabove, the flow meters 165 a to 168 a measure the amount of gas flowingout of the areas 135 to 138.

The determination means 1A determines whether the substrate W isadsorbed to the top ring 1 based on at least the measurement result ofthe flow meter 165 a by considering the measurement results of thepressure gauges 161 b to 164 b and, as needed, the flow meters 166 a to168 a (step S6).

FIG. 9 is a diagram schematically showing the measurement results of thepressure gauge 164 b and the flow meter 165 a after starting thevacuuming. The vertical axis on the left side indicates the pressure andthe vertical axis on the right side indicates the flow volume (thedirection flowing out from the area 135 is defined as positive). Whenthe vacuuming is started at a time point t0, the pressure in the area134 decreases and becomes close to vacuum from the atmospheric pressure.On the other hand, when the vacuuming is started, the volume of the area135 decreases, and accordingly, gas outflow from the area 135 occurs.

The determination means 1A can determine whether the substrate W isfully adsorbed to the membrane 13, in other words, whether the transferof the substrate W has been completed, based on an amount of gas flowingout of the area 135. As a specific example, the determination means 1Amay determine that the transfer has been completed at a time point (timet1) when the amount of outflowing gas reaches a predetermined thresholdvalue Fth or at a time point (time t2) when the amount of outflowing gasbecomes local maximum, that is, when the amount of outflowing gaschanges from increase to decrease. Alternatively, the determinationmeans 1A may determine that the transfer has been completed at a timepoint when a total amount of outflowing gas, that is, a time integrationvalue of the amount of outflowing gas, reaches a predetermined thresholdvalue. Further, the determination means 1A may determine by using aderivative value or a difference value of the amount of outflowing gas.

A largest gas outflow occurs in the area 135 near the areas 131 to 134that are vacuum drawn. Therefore, although it is desirable that thedetermination means 1A performs the determination based on the amount ofgas flowing out of the area 135, the determination means 1A may performthe determination based on the amount of gas flowing out of the areas136 to 138 instead of or in addition to the amount of gas flowing out ofthe area 135.

To perform the determination more accurately, the determination means 1Amay determine whether the transfer of the substrate W has been completedby considering also the pressure of the area 134. For example, when theabove conditions related to the amount of outflowing gas are satisfiedand further the pressure of the area 134 reaches a predeterminedthreshold value, it may be determined that the transfer has beencompleted. The determination may be performed based on the pressures ofthe areas 131 to 133 instead of or in addition to the pressure of thearea 134.

The determination means 1A of the present embodiment performs thedetermination by using the flow volume of the gas in an area which isnot vacuum drawn. To detect a volume change of the area shown in FIG.8B, it can be considered to use the pressure of the area and to use theflow volume of the gas, and the latter is preferable. This is becausewhen the pressure gauge is installed at a position away from the area,it may not be possible to measure the pressure of the area quickly andaccurately.

Referring back to FIG. 7A. When the determination means 1A determinesthat the substrate W is adsorbed to the top ring 1 (YES in step S6), thetop ring 1 moves upward and the transport mechanism 600 b moves downward(step S7). In other words, the membrane 13 to which the substrate W isadsorbed and the transport mechanism 600 b are separated from eachother. The top ring 1 and the transport mechanism 600 b are separatedfrom each other after the determination means 1A performs thedetermination based on the flow volume, it is possible to prevent thesubstrate W from falling due to insufficient adsorption of the substrateW.

On the other hand, When the determination means 1A determines that thesubstrate W is not adsorbed to the top ring 1 (NO in step S6), theprocess moves to a retry mode.

As an example of the retry mode, the areas 131 to 138 are opened to theatmosphere (step S31), and the process may return to step S3 to retrythe vacuuming.

As another example of the retry mode, the areas 131 to 138 arepressurized at a low pressure (for example, 50 hPa) (step S32),thereafter, the areas 131 to 138 are opened to the atmosphere (stepS31), and the process may return to step S3 to retry the vacuuming.Thereby, it is possible to more reliably restore the volumes of theareas 131 to 138 and then perform vacuuming again.

As further another example of the retry mode, the top ring shaft 2 (seeFIGS. 2A and 2B) is slightly (for example, 1 to 2 mm) moved upward (stepS33), thereafter, the areas 131 to 138 are pressurized at a low pressureas needed (step S32), thereafter, the areas 131 to 138 are opened to theatmosphere (step S31), thereafter, the top ring shaft 2 is moveddownward to the original position (step S34), and then the process mayreturn to step S3 to retry the vacuuming. Thereby, it is possible tofurther reliably restore the volumes of the areas 131 to 138 and thenperform vacuuming again.

As shown in FIG. 7B, before the substrate W and the membrane 13 comeinto contact with each other (step S2), that is, for example, while orbefore the top ring 1 moves downward and the transport mechanism 600 bmoves upward (step S1) or before the movements, the pressure controlmeans 15 pressurizes at least one of the areas 131 to 138, preferablythe area that is vacuum drawn in step S3 (step S41). Further, after thepressurization, the area that is vacuum drawn may be set to anatmospheric pressure state by the pressure control means 15 or the areamay be set to an atmospheric pressure state by providing a third valve(not shown in the drawings), which is branched in the same manner as thearrangement of the valves 171 (the valves 171 a and 171 b) and cancommunicate with the atmosphere, in addition to the valves 171, andopening only the third valve (step S42).

Thereby, even if the upper surface of the membrane 13 and the lowersurface of the top ring body 11 are in a state of being closely incontact with each other, the state is cancelled by pressurization andthe lower surface of the membrane 13 becomes a flat or downward convexshape with respect to the substrate W. As a result, it is possible toincrease the area where the substrate W and the membrane 13 are incontact with each other. In particular, when the membrane 13 has adownward convex shape, it is possible to cause a central portion of thesubstrate W to be reliably in contact with the membrane 13. Thesubstrate W is reliably adsorbed by vacuuming the central area in thisstate. Further, by performing such pressurization in advance before thesubstrate W and the membrane 13 come into contact with each other, it ispossible to avoid degradation of throughput.

As described above, in the first embodiment, when the substrate W istransferred from the transport mechanism 600 b to the top ring 1, it isdetermined whether the substrate W is adsorbed to the top ring 1 basedon the flow volume of the gas flowing out of an area located outside thearea that is vacuum drawn. Therefore, it is possible to accuratelydetect the completion of the transfer. Further, the completion of thetransfer can be accurately detected even when there is an individualdifference in the surfaces of the substrate W and the membrane 13, sothat the transfer time of the substrate W can be optimized and thethroughput improves.

The pressure control means 15 described in FIG. 6 is only an example andvarious modifications are possible.

For example, as shown in FIG. 10, a pipe is branched into a fork and apressure gauge P may be arranged between an arbitrary area and thebranch point. The fluid supply source 18 may be arranged at a tip of onebranch, and a valve and a flow meter F may be arranged between thebranch point and the fluid supply source 18. The vacuum source 19 may bearranged at a tip of the other branch, and a valve and a pressure gaugeP may be arranged between the branch point and the vacuum source 19.When the fluid supply source 18 is, for example, an electropneumaticregulator, a state equivalent to open to the atmosphere is obtained bysetting a pressure command to the atmospheric pressure (zero pressure).

As shown in FIG. 11, a pipe is branched into three and a pressure gaugeP may be arranged between an arbitrary area and the branch point. Thefluid supply source 18 may be arranged at a tip of one branch, and avalve and a flow meter F may be arranged between the branch point andthe fluid supply source 18. The vacuum source 19 may be arranged at atip of another branch, and a valve and a pressure gauge P may bearranged between the branch point and the vacuum source 19. Further, atip of the other branch may be opened to the atmosphere, and a valve anda flow meter F may be arranged between the tip and the branch point.

Second Embodiment

The first embodiment described above is related to an operation in whichthe substrate W is transferred from the transport mechanism 600 b to thetop ring 1. On the other hand, in a second embodiment described below isrelated to an operation in which the substrate W is adsorbed to the topring 1 when the top ring 1 is detached from the polishing table 3 afterthe polishing of the substrate W has been completed. Hereinafter,differences from the first embodiment will be mainly described.

FIG. 12 is a flowchart showing an adsorption procedure of the substrateW including an adsorption completion determination of the substrate W.The same processes as those in FIG. 7A are denoted by the same referencesymbols.

The polishing of the substrate W held by the top ring 1 is completed inthe manner as described with reference to FIGS. 2A and 2B (step S11). Inthis state, the upper surface of the substrate W is in contact with thelower surface of the membrane 13 by using the polishing table 3 as asupport member. When polishing the substrate W, any of the areas 131 to138 may be pressurized to press the substrate W against the polishingtable 3 in order to efficiently perform the polishing. Therefore, whenthe substrate W is moved from the polishing table 3 after the completionof the polishing, it is necessary to cause the substrate W to beadsorbed to the top ring 1 again.

Therefore, the operation of steps S3 to S6 is performed in the samemanner as in FIG. 7A. Specifically, first, the pressure control means 15performs vacuuming of the central area (step S3). Here, there is thepolishing liquid supplied from the nozzle 4 between the polishingsurface 3 a and the substrate W. Therefore, a somewhat high adsorptionforce is required to cause the substrate W to be separated from thepolishing surface 3 a and to be adsorbed to the top ring 1. Therefore,even in a case in which only the central area 131 has to be vacuum drawnwhen the substrate is transferred from the transport mechanism 600 b tothe top ring 1 as described in the first embodiment, the areas 131 to134 may be required to be vacuum drawn in the present embodiment.

Thereafter, each pressure gauge measures the pressure of an area that isvacuum drawn (step S4) and each flow meter measures the flow volume ofan area outside the areas that are vacuum drawn (step S5). Then, thedetermination means 1A determines whether the substrate W is adsorbed tothe top ring 1 (more specifically, the lower surface of the membrane 13of the top ring 1) (step S6). When the adsorption is confirmed, the topring 1 moves upward (step S12), so that the membrane 13 to which thesubstrate W is adsorbed is separated from the polishing table 3.

As described above, in the second embodiment, when the substrate W isadsorbed to the top ring 1 after the polishing of the substrate W, it isdetermined whether the substrate W is adsorbed to the top ring 1 basedon the flow volume of the gas flowing out of areas located outside theareas that are vacuum drawn. Therefore, it is possible to accuratelydetect the completion of the adsorption in the same manner as in thefirst embodiment. Further, the completion of the transfer can beaccurately detected even when there is an individual difference in thesurfaces of the substrate W and the membrane 13, so that the adsorptiontime of the substrate W can be optimized and the throughput improves.

Third Embodiment

As described in BACKGROUND AND SUMMARY, the substrate is vacuum drawnfrom a hole formed in the membrane, so that the substrate is adsorbed tothe membrane. However, there is a case in which liquid such as waterenters an area that includes the hole and thereby the pressure appliedto the substrate becomes unstable. Therefore, in recent years, the holeformed in the membrane tends to be small as much as possible. Further,the substrate may be adsorbed by deforming the surface shape of themembrane by vacuuming without using the hole.

When the hole is small or no hole is made, a force of adsorbing thesubstrate becomes small. If the top ring is moved before the substrateis sufficiently adsorbed to the top ring, the substrate may fall.Therefore, it is necessary to detect that the substrate is adsorbed tothe top ring and the transfer from the transport mechanism is completed.Normally, the vacuum pressure of the area that is vacuum drawn ismeasured, and it is determined that the transfer of the substrate iscompleted when the vacuum pressure reaches a predetermined thresholdvalue.

However, even when the determination is performed based on the vacuumpressure of the area that is vacuum drawn, a sufficient adhesive forceis not necessarily generated between the substrate and the membrane.Therefore, for safety's sake, it is required to set a severe thresholdvalue or move the top ring after waiting a predetermined time when thethreshold value is reached. Doing so makes the transfer time of thesubstrate longer than the time originally required, so that there is aproblem that the throughput decreases.

Further, even after the substrate is once adsorbed, there may be a casein which the adsorption force decreases when the top ring transports thesubstrate and the substrate falls.

The third to the sixth embodiments have been made in view of the aboveproblems and an object of the third to the sixth embodiments are toprovide an elastic film and a substrate holding apparatus that canappropriately handle a substrate, a substrate polishing apparatusincluding such substrate holding apparatus, and a substrate adsorptiondetermination method and a pressure control method for such substrateholding apparatus.

FIG. 13 is a schematic cross-sectional view of the substrate polishingapparatus 300 according to the present embodiment. FIG. 13 correspondsto FIG. 2B. Hereinafter, the present embodiment will be described withreference to FIGS. 2A and 13. The substrate polishing apparatus 300includes a top ring 1, a top ring shaft 2 where the top ring 1 isconnected to a lower part of the top ring shaft 2, a polishing table 3having a polishing pad 3 a, a nozzle 4 that supplies polishing liquid onthe polishing table 3, a top ring head 5, and a support shaft 6.

The top ring 1 holds the substrate W, and as shown in FIG. 13, the topring 1 includes a top ring body 11 (a carrier), a ring-shaped retainerring 12, a flexible membrane 13 (an elastic film) that is provided belowthe top ring body 11 and inside the retainer ring 12, an air bag 14provided between the top ring body 11 and the retainer ring 12, and apressure control apparatus 7.

The retainer ring 12 is provided on the outer circumference portion ofthe top ring body 11. The circumferential edge of the held substrate Wis surrounded by the retainer ring 12, so that the substrate W does notrun away from the top ring 1 during polishing. The retainer ring 12 maybe a single member or may have a double ring structure including aninner ring and an outer ring provided outside the inner ring. In thelatter case, it is possible that the outer ring is fixed to the top ringbody 11 and an air bag 14 is provided between the inner ring and the topring body 11.

The membrane 13 is provided facing the top ring body 11. The uppersurface of the membrane 13 forms a plurality of concentric areas betweenthe membrane 13 and the top ring body 11. By depressing one or aplurality of areas, the lower surface of the membrane 13 can hold theupper surface of the substrate W.

The air bag 14 is provided between the top ring body 11 and the retainerring 12. The retainer ring 12 can relatively move in the verticaldirection with respect to the top ring body 11 by the air bag 14.

The pressure control apparatus 7 supplies fluid to areas between the topring body 11 and the membrane 13, performs vacuuming of the areas, andopens the areas to the atmosphere, so that the pressure controlapparatus 7 individually adjusts the pressure of each area formedbetween the top ring body 11 and the membrane 13. Further, the pressurecontrol apparatus 7 determines whether the substrate W is adsorbed tothe membrane 13. The configuration of the pressure control apparatus 7will be described later in detail.

In FIG. 2A, the lower end of the top ring shaft 2 is connected to thecenter of the upper surface of the top ring 1. An elevating mechanismnot shown in the drawings moves up and down the top ring shaft 2, sothat the lower surface of the substrate W held by the top ring 1 isattached to and detached from the polishing pad 3 a. Further, a motornot shown in the drawings rotates the top ring shaft 2, so that the topring 1 rotates and the substrate W held by the top ring 1 also rotates.

The polishing pad 3 a is provided on the upper surface of the polishingtable 3. The lower surface of the polishing table 3 is connected to arotating shaft, so that the polishing table 3 is rotatable. Thepolishing liquid is supplied from the nozzle 4, and the substrate W andthe polishing table 3 rotate in a state in which the lower surface ofthe substrate W is in contact with the polishing pad 3 a, so that thesubstrate W is polished.

The top ring shaft 2 is connected to one end of the top ring head 5 inFIG. 13 and the support shaft 6 is connected to the other end of the topring head 5. When a motor not shown in the drawings rotates the supportshaft 6, the top ring head 5 swings, so that the top ring 1 moves backand forth between a position on the polishing pad 3 a and a substratetransfer position (not shown in the drawings).

Next, an operation to transfer the substrate from the transportmechanism 600 b in FIG. 1 to the top ring 1 in FIGS. 2A and 13 will bedescribed with reference to FIGS. 3A to 3C and 4.

As shown in FIG. 3A, the substrate W is mounted on the hand 601 of thetransport mechanism 600 b. The retainer ring station 800 is used for thetransfer of the substrate W. The retainer ring station 800 has a push-uppin 801 that pushes up the retainer ring 12 of the top ring 1. Althoughthe retainer ring station 800 may have a release nozzle, the releasenozzle is not shown in the drawings.

As shown in FIG. 4, the hand 601 supports parts of outer circumferenceof the lower surface of the substrate W. The push-up pin 801 and thehand 601 are arranged not to be in contact with each other.

In a state shown in FIG. 3A, the top ring 1 moves downward and thetransport mechanism 600 b moves upward. The top ring 1 moves downward,so that the push-up pin 801 pushes up the retainer ring 12 and thesubstrate W approaches the membrane 13. When the transport mechanism 600b moves further upward, the upper surface of the substrate W comes intocontact with the lower surface of the membrane 13 (FIG. 3B).

In this state, an area formed between the membrane 13 and the top ringbody 11 is depressurized, so that the substrate W is adsorbed to thelower surface of the membrane 13 of the top ring 1. However, dependingon circumstances, there may be a case in which the substrate W is notadsorbed to the lower surface of the membrane 13, or the substrate Wfalls after once being adsorbed. Therefore, in the present embodiment, adetermination of whether the substrate W is adsorbed to the membrane 13(a substrate adsorption determination) is performed as described later.

Thereafter, the transport mechanism 600 b moves downward (FIG. 3C).

Next, the top ring 1 will be described.

FIG. 14A is a cross-sectional view schematically showing a structure ofthe top ring 1 in the third embodiment. Circumferential walls 13 a to 13h extending upward toward the top ring body 11 are formed on themembrane 13. By these circumferential walls 13 a to 13 h, concentricareas 131 to 138, which are divided by the circumferential walls 13 a to13 h, are formed between the upper surface of the membrane 13 and thelower surface of the top ring body 11. It is desirable that no hole isformed in the lower surface of the membrane 13.

Flow paths 141 to 148 which penetrate the top ring body 11 and whose oneends communicate with the areas 131 to 138, respectively, are formed. Anair bag 14 made of an elastic film is provided directly on the retainerring 12 and a flow path 149 whose one end communicates with the air bag14 is formed in the same manner. The other ends of the flow paths 141 to149 are connected to the pressure control apparatus 7. Pressure sensorsand flow volume sensors may be provided on the flow paths 141 to 149.

Further, for the substrate adsorption determination, a flow path 150which penetrates the top ring body 11 and whose one end communicateswith the area 131 is formed. The other end of the flow path 150 isopened to the atmosphere.

The pressure control apparatus 7 includes valves V1 to V9 and pressureregulators R1 to R9 which are respectively provided to the flow paths141 to 149, a controller 71, and a pressure adjustor 72. Further, forthe substrate adsorption determination, the pressure control apparatus 7includes a valve V10 and a flow meter FS which are provided on the flowpath 150 and a determination unit 73. When the valve V10 is closed, noflow occurs, so that an arrangement order of the valve V10 and the flowmeter FS does not matter.

The controller 71 controls the valves V1 to V10, the pressure regulatorsR1 to R9, and the pressure adjustor 72.

The pressure adjustor 72 is connected to one ends of the flow paths 141to 149 and performs pressure adjustment of the areas 131 to 138 and theair bag 14 according to control of the controller 71. Specifically, thepressure adjustor 72 pressurizes the areas 131 to 138 and the airbag 14by supplying a fluid such as air through the flow paths 141 to 149,depressurizes the areas 131 to 138 and the air bag 14 by performingvacuuming, and opens the areas 131 to 138 and the air bag 14 to theatmosphere.

In the case of FIG. 14A, an example is shown in which the valves V1 toV9 are connected to the flow paths 141 to 149, respectively. FIG. 14B isa modified example of FIG. 14A and a plurality of valves may beconnected to each of the flow paths 141 to 149. As an example, FIG. 14Bshows a case in which three valves V3-1, V3-2, and V3-3 are connected tothe flow path 143. The valve V3-1 is connected to a pressure regulatorR3, the valve V3-2 is connected to an atmosphere open source, and thevalve V3-3 is connected to a vacuum source. When pressurizing the area133, the valves V3-2 and V3-3 are closed, the valve V3-1 is opened, andthe pressure regulator R3 is activated. When causing the area 133 to bein an atmosphere open state, the valves V3-1 and V3-3 are closed and thevalve V3-2 is opened. When causing the area 133 to be in a vacuum state,the valves V3-1 and V3-2 are closed and the valve V3-3 is opened.

In FIG. 14A, for example, to pressurize the area 135, the controller 71opens the valve V5 and controls the pressure adjustor 72 so that air issupplied to the area 135. This is simply represented as the controller71 pressurizes the area 135″ or the like.

The flow meter FS measures a flow volume of fluid flowing in the flowpath 150, in other words, a flow volume of fluid flowing to the area131, and notifies the determination unit 73 of a measurement result.Unless otherwise noted, the flow volume is a volume of fluid (inparticular, air) flowing per unit time. The arrangement position of theflow meter FS is not limited as long as the flow meter FS can measurethe flow volume of the flow path 150. The flow path 141 and the flowpath 150 are connected to each other, so that the flow meter FS may bearranged, for example, in the flow path 141.

The determination unit 73 performs the substrate adsorptiondetermination based on the flow volume measured by the flow meter FS.

FIG. 15 is a cross-sectional view showing details of the top ring body11 and the membrane 13 in the top ring 1. As shown in FIG. 15, themembrane 13 includes a circular contact portion 130 that comes intocontact with the substrate W and eight circumferential walls 13 a to 13h that are directly or indirectly connected to the contact portion 130.The contact portion 130 holds the substrate W by coming into contactwith the rear surface of the substrate W, that is, a surface opposite tothe surface to be polished. The contact portion 130 presses thesubstrate W against the polishing pad 3 a during polishing. Thecircumferential walls 13 a to 13 h are concentrically arrangedring-shaped circumferential walls.

The upper ends of the circumferential walls 13 a to 13 h are sandwichedby holding rings 22, 24, 26, and 28 and the lower surface of the topring body 11, and are attached to the top ring body 11. The holdingrings 22, 24, 26, and 28 are detachably fixed to the top ring body 11 bya holding means (not shown in the drawings). Therefore, when the holdingmeans is unlocked, the holding rings 22, 24, 26, and 28 are detachedfrom the top ring body 11, so that the membrane 13 can be removed fromthe top ring body 11. A screw and the like may be used as the holdingmeans.

The holding rings 22, 24, 26, and 28 are located inside the areas 132,134, 136, and 138, respectively. The flow paths 142, 144, 146, and 148penetrate the top ring body 11 and the holding rings 22, 24, 26, and 28,respectively. The top ring body 11 has protrusion portions 21, 23, 25,and 27 that protrude downward toward the areas 131, 133, 135, and 137,respectively. The flow paths 141, 143, 145, and 147 penetrate theprotrusion portions 21, 23, 25, and 27, respectively. Although not shownin the drawings, the flow path 150 penetrates the protrusion portion 21.

It is desirable that the lower surfaces of the holding rings 22, 24, 26,and 28 and those of the protrusion portions 21, 23, 25, and 27 are onthe same plane. This is because these lower surfaces form a referencesurface when the substrate W is adsorbed and held.

There is a gap g (shown later in FIG. 19 and the like), through whichair can flow from the flow path 141 to the flow path 150, between theselower surfaces and the membrane 13. When the substrate W is adsorbed tothe lower surface of the membrane 13, the membrane 13 is drawn up towardthe top ring body 11, so that the gap g almost disappears. If the gap gis too small, a difference of change of the gap g is small between whenthe substrate W is adsorbed and when the substrate W is not adsorbed, asa result, a margin of determination becomes small. On the other hand, ifthe gap g is too large, it is necessary to largely contract thecircumferential walls 13 a to 13 h of the membrane 13 when adsorbing thesubstrate. As a result, a downward repulsive force from thecircumferential walls 13 a to 13 h to the substrate W becomes large, sothat the adsorption force decreases or the substrate may be damaged.

It is necessary to appropriately set the width of the gap g byconsidering the above. Specifically, the width of the gap g is desirableto be about 0.1 to 2 mm, and is more desirable to be about 0.5 mm.

FIG. 16 is a cross-sectional view taken along line A-A′ in FIG. 15. Asshown in FIG. 16, a hole 21 a that communicates with the flow path 141(FIG. 14A) and a hole 21 b that communicates with the flow path 150 areformed in the protrusion portion 21. Holes 23 a, 25 a, and 27 a thatcommunicate with the flow paths 143, 145, and 147, respectively, areformed in the protrusion portions 23, 25, and 27, respectively. Holes 22a, 24 a, and 26 a that communicate with the flow paths 142, 144, and146, respectively, are formed in the holding rings 22, 24, and 26,respectively. The number of the holes and the arrangement of the holesare not particularly limited.

FIG. 17 is a diagram for explaining an operation of each valve in thetop ring 1. When adsorbing or polishing the substrate W, the pressuresof any one or more of the areas 132 to 137 should be adjusted.Hereinafter, a case in which the pressure of the area 133 is adjustedwill be described, and the pressures of the other areas 132 and 134 to137 can be arbitrarily adjusted.

When opening the membrane 13 during idling or the like, the controller71 opens the valves V1, V3, and V10 and opens the areas 131 and 133 tothe atmosphere.

When polishing the substrate W, the controller 71 opens the valves V1and V3 to pressurize the areas 131 and 133 and closes the valve V10 inorder to pressurize the membrane 13 to press the substrate W against thepolishing pad 3 a.

When the substrate W is transferred from the transport mechanism 600 bto the top ring 1 to be adsorbed by the membrane 13, the controller 71opens the valve V3 to depressurize the area 133. Further, to perform thesubstrate adsorption determination, the controller 71 opens the valveV10 to open the area 131 to the atmosphere while opening the valve V1 tosomewhat pressurize the area 131. Then, based on a value measured by theflow meter FS, the determination unit 73 determines whether thesubstrate is adsorbed to the membrane 13 as described below.

FIG. 18 is a flowchart showing a procedure of the substrate adsorptiondetermination. Hereinafter, the area 131 where the flow meter FS isprovided is referred to as a “determination area” and the area 133 whichis depressurized for adsorption is referred to as an “adsorption area”.

First, the controller 71 depressurizes the adsorption area 133 (stepS1). Then, the controller 71 opens the valve V1 to pressurize thedetermination area 131 and opens the valve V10 to open the determinationarea 131 to the atmosphere (step S2). In other words, while thecontroller 71 pressurizes the determination area 131 through the flowpath 141, the controller 71 opens the determination area 131 to theatmosphere through the flow path 150.

In step S1, the controller 71 depressurizes the adsorption area 133 toabout −500 hPa. On the other hand, in step S2, the controller 71pressurizes the adsorption area 131 to about 200 hPa or less anddesirably to about 50 hPa. This is because when the determination area131 is too pressurized, a force applied downward to the substrate Wincreases and the force impedes adsorption of the substrate.

Subsequently, the determination unit 73 waits until a predetermineddetermination start time T0 elapses (step S3). When the determinationstart time T0 elapses, the determination unit 73 compares a flow volumemeasured by the flow meter FS and a predetermined threshold value anddetermines whether the substrate W is adsorbed to the membrane 13 (stepS4).

FIG. 19 is a diagram schematically showing cross sections of themembrane 13 and the top ring body 11 when the adsorption fails. Themembrane 13 has flexibility, so that when the substrate W is notadsorbed, although a part of the membrane 13 corresponding to theadsorption area 133 is drawn up to the top ring body 11, a part of themembrane 13 corresponding to the determination area 131 is not drawn upand a gap g remains between the part and the top ring body 11.Therefore, the flow volume measured by the flow meter FS becomes large.

FIG. 20 is a diagram schematically showing cross sections of thesubstrate W, the membrane 13, and the top ring body 11 when theadsorption succeeds. When the substrate W is adsorbed, the entiremembrane 13 including the area corresponding to the determination area131 is drawn up and the membrane 13 is closely attached to the top ringbody 11. Therefore, the gap g almost disappears and the flow volumemeasured by the flow meter FS becomes small.

As known from the above, the flow volume of fluid flowing in thedetermination area 131 corresponds to the size of the gap g, and thegreater the gap g is, the greater the flow volume is.

Therefore, when the flow volume is smaller than or equal to thethreshold value (that is, when the gap g is small), the determinationunit 73 determines that the adsorption of the substrate W succeeds (orthe substrate W is adsorbed) (YES in step S4 in FIG. 18, S5, and FIG.20). The substrate processing apparatus continues an operation such astransport of the substrate W by the top ring 1 (step S6). Thereafter,when the adsorption of the substrate W should continue (YES in step S7),the determination of step S4 is repeatedly performed.

On the other hand, when the flow volume is greater than the thresholdvalue (that is, when the gap g is large) even after a predeterminederror confirmation time elapses, the determination unit 73 determinesthat the adsorption of the substrate W fails (or the substrate W is notadsorbed) (NO in S4, YES in S8, S9, and FIG. 19). The substrateprocessing apparatus stops operation and transmits error information asneeded (step S10).

In the present embodiment, even after it is confirmed that the substrateW is adsorbed to the membrane 13, the determination is continuouslyperformed (YES in step S7, and S4). Therefore, when the substrate Wfalls while the substrate W is being transported and so on, the flowvolume becomes greater than the threshold value, so that it is possibleto detect that the substrate W is not present (step S9).

FIG. 21 is a diagram schematically showing flow volumes measured by theflow meter FS after starting the adsorption. The solid line indicates aflow volume measured by the flow meter FS in a case in which theadsorption succeeds. The dashed line indicates a flow volume measured bythe flow meter FS in a case in which the adsorption fails. Thedashed-dotted line indicates a flow volume measured by the flow meter FSin a case in which the adsorption once succeeds but the substrate Wfalls after that. The horizontal axis indicates time.

As shown in FIG. 21, when the adsorption is started at a time point t1(step S1 in FIG. 18), the flow volume increases. This is because,regardless of success or failure of the adsorption, at the time pointwhen the adsorption is started, there is a gap g between the uppersurface of the membrane 13 and the lower surface of the top ring body11, so that air flows.

When the adsorption succeeds (the solid line in FIG. 21), the substrateW is adsorbed to the membrane 13, so that the gap g between the membrane13 and the top ring body 11 becomes small. Therefore, after a certaintime point t2, the flow volume begins to decrease. At a time point t3 atwhich the flow volume becomes smaller than the threshold value, it isdetermined that the adsorption succeeds (step S5 in FIG. 18).Thereafter, when the substrate W is completely adsorbed to the membrane13 at a time point t4 in FIG. 21, the gap g between the membrane 13 andthe top ring body 11 almost disappears, so that the flow volume becomessubstantially constant.

If the substrate W falls from the top ring 1 at a time point t11, theflow volume increases again (the dashed-dotted line in FIG. 21). This isbecause the substrate W is separated from the membrane 13 and thereforethe gap g is generated again between the membrane 13 and the top ringbody 11. In this case, after a predetermined error confirmation timeelapses from a time point t12 at which the flow volume becomes greaterthan the threshold value (step S8), it is determined that the adsorptionfails (step S9 in FIG. 18).

On the other hand, when the adsorption fails (the dashed line in FIG.21), the flow volume continues to increase also after the time point t2and becomes constant before long. Therefore, the flow volume is stillgreater than the threshold value even after the error confirmation timeelapses, so that it is determined that the adsorption fails (step S9 inFIG. 18).

The reason why the determination start time TO is set is to prevent thesubstrate from being determined to be adsorbed to the membrane beforethe substrate is fully adsorbed to the membrane (before a time point t5in FIG. 21). The error confirmation time is required also in the casedescribed below. This is because when the substrate W adsorbed to thetop ring 1 is drawn up from the polishing pad 3 a after the polishing,the flow volume may temporarily increase and exceed the threshold valuedue to an adsorption force between the polishing pad 3 a and thesubstrate W.

As described above, in the third embodiment, the determination area 131is pressurized and opened to the atmosphere, and the flow volume of thearea 131 is measured. The flow volume corresponds to the size of the gapg between the membrane 13 and the top ring body 11. Therefore, it ispossible to accurately determine whether the adsorption of the substrateW succeeds by monitoring the flow volume, so that it is possible toappropriately handle the substrate W. Further, it is possible tocontinue the determination after the substrate W is adsorbed, so thateven when the substrate W falls after the adsorption once succeeds, itis possible to detect that the substrate W falls.

In the present embodiment, the flow path 150 is opened to theatmosphere. However, for example, the flow volume may be adjusted in aflow volume range appropriate to detect the adsorption of the substrateby using the valve V10 as a flow volume adjustment valve, or the flowvolume may be adjusted or air may be exhausted by connecting a pressureregulator instead of opening the flow path to the atmosphere. Whenconnecting a pressure regulator to the flow path 150, for example, R1 isset to 100 hPa pressure and the added pressure regulator is set to 50hPa pressure, and thereby air is flown through the flow path 150.

It is possible to apply the substrate adsorption determination of thepresent embodiment to the membrane 13 where no hole is formed. Further,the valve V10 is opened when the substrate adsorption determination isperformed, so that the determination area 131 is not closed and thepressure of the determination area 131 does not become so high.Therefore, the determination area 131 in the membrane 13 rarely appliesstress to the substrate W.

In the present embodiment, the central area 131 is used as thedetermination area and the area 133 is used as the adsorption area.However, other areas may be used as the determination area and theadsorption area. In other words, it is possible to form thedetermination area by providing a configuration corresponding to thevalve V10, the flow path 150, and the flow meter FS in at least onearea, and it is possible to define the other areas as the adsorptionareas.

It is desirable that the determination area is not adjacent to theadsorption area and there are one or more areas between these areas. Ifthe determination area is adjacent to the adsorption area, even if theadsorption of the substrate W fails, a part of the membrane 13corresponding to the adsorption area is drawn up, and accordingly a partcorresponding to the determination area may also be drawn up. In thiscase, the flow volume of fluid flowing through the determination areadecreases and erroneous determination may occur.

Fourth Embodiment

In the third embodiment described above, the flow volume of fluidflowing through the determination area 131 is directly measured by theflow meter FS. However, another physical amount may be measured by usinga measuring instrument whose measurement value varies according to theflow volume. Therefore, in a fourth embodiment described below, anexample in which a pressure gauge is used instead of the flow meter FSwill be described.

FIG. 22 is a cross-sectional view schematically showing a structure ofthe top ring 1 in the fourth embodiment. Different from FIG. 14A, apressure gauge PS is provided in the flow path 141 that communicateswith the determination area 131. The pressure gauge PS measures thepressure of the flow path 141 and notifies the determination unit 73 ofthe measurement result. The pressure measured by the pressure gauge PScorresponds to the flow volume of fluid flowing through thedetermination area 131.

FIG. 23 is a diagram schematically showing cross sections of themembrane 13 and the top ring body 11 when the adsorption fails. FIG. 23corresponds to FIG. 19. As shown in FIG. 23, there is a gap g betweenthe determination area 131 and the membrane 13. The flow volume of thedetermination area 131 is large. In this case, gas can easily flow fromthe flow path 141 to the determination area 131, so that the pressure inthe flow path 141 is low. As a result, the measurement result of thepressure gauge PS is low.

FIG. 24 is a diagram schematically showing cross sections of thesubstrate W, the membrane 13, and the top ring body 11 when theadsorption succeeds. FIG. 24 corresponds to FIG. 20. As shown in FIG.24, there is rarely a gap g between the determination area 131 and themembrane 13. The flow volume of the determination area 131 is small. Inthis case, gas cannot easily flow from the flow path 141 to thedetermination area 131, so that the pressure in the flow path 141 ishigh. As a result, the measurement result of the pressure gauge PS ishigh.

In this way, the pressure gauge PS corresponds to the flow volume.Therefore, it should be determined whether the pressure exceeds athreshold value instead of step S4 in FIG. 18 (whether the flow volumeis smaller than or equal to the threshold value).

FIG. 25 is a cross-sectional view schematically showing a structure ofthe top ring 1 which is a modified example of FIG. 22. Different fromFIG. 22, the pressure gauge PS is provided in the flow path 150 thatcommunicates with the determination area 131. The pressure gauge PSmeasures the pressure of the flow path 150 and notifies thedetermination unit 73 of the measurement result. The pressure measuredby the pressure gauge PS corresponds to the flow volume of fluid flowingthrough the determination area 131.

FIG. 26 is a diagram schematically showing cross sections of themembrane 13 and the top ring body 11 when the adsorption fails. FIG. 26corresponds to FIG. 19. As shown in FIG. 26, there is a gap g betweenthe determination area 131 and the membrane 13. The flow volume of thedetermination area 131 is large. In this case, gas can easily flow fromthe determination area 131 to the flow path 150, so that the pressure inthe flow path 150 is high. As a result, the measurement result of thepressure gauge PS is high.

FIG. 27 is a diagram schematically showing cross sections of thesubstrate W, the membrane 13, and the top ring body 11 when theadsorption succeeds. FIG. 27 corresponds to FIG. 20. As shown in FIG.27, there is rarely a gap g between the determination area 131 and themembrane 13. The flow volume of the determination area 131 is small. Inthis case, gas cannot easily flow from the determination area 131 to theflow path 150, so that the pressure in the flow path 150 is low. As aresult, the measurement result of the pressure gauge PS is low.

In this way, the pressure gauge PS corresponds to the flow volume.Therefore, it should be determined whether the pressure is greater thanor equal to a threshold value instead of step S4 in FIG. 18 (whether theflow volume is smaller than or equal to the threshold value).

As described above, in the fourth embodiment, it is possible toaccurately determine whether the adsorption of the substrate W succeedsby measuring the pressure that varies according to the flow volume.

Fifth Embodiment

A main object of a fifth embodiment is to reliably release the substrateadsorbed to the top ring. Hereinafter, differences from the thirdembodiment will be mainly described.

FIGS. 28A to 28C and 29 are diagrams for explaining in detail thetransfer of the substrate from the top ring 1 to the transport mechanism600 b. FIGS. 28A to 28C are diagrams of the transport mechanism 600 band the top ring 1 as seen from side and FIG. 29 is a diagram of the topring 1 and the retainer ring station 800 as seen from above (thetransport mechanism 600 b in FIG. 28 is omitted). As shown in thesefigures, the retainer ring station 800 has, for example, three releasenozzles 802 facing inside (facing the substrate W).

FIG. 28A shows a state in which the substrate W is adsorbed to themembrane 13. At this time, fluid (release shower) is not jetted from therelease nozzles 802.

As shown in FIG. 28B, the top ring 1 moves downward and the transportmechanism 600 b moves upward. Thereby, the hand 601 of the transportmechanism 600 b approaches the lower surface of the substrate W.However, the hand 601 does not come into contact with the lower surface.Further, the push-up pin 801 pushes up the retainer ring 12.

In this state, an area (hereinafter assumed as the area 133) between themembrane 13 and the top ring body 11 is pressurized. Further, a fluidsuch as air is jetted from the release nozzles 802. Thereby, thesubstrate W is released from the membrane 13 and is mounted on the hand601. Details of this point will be described later.

Thereafter, as shown in FIG. 28C, the hand 601 on which the substrate Wis mounted moves downward and the top ring 1 moves upward.

The release in FIG. 28B will be described in detail.

FIG. 30 is a diagram schematically showing a state before starting therelease. Before starting the pressurization of the area 133, thesubstrate W is adsorbed to the membrane 13, so that there is hardly agap g between the upper surface of the membrane 13 and the lower surfaceof the top ring body 11. Before starting the pressurization, no fluid isjetted from the release nozzles 802.

FIG. 31 is a diagram schematically showing a state after starting therelease. When starting the pressurization of the area 133, the membrane13 swells and the gap g between the upper surface of the membrane 13 andthe top ring body 11 gradually increases. In other words, the membrane13 moves downward. In this state, a fluid is jetted from the releasenozzles 802. However, the fluid hits the lower side of the substrate Wand rarely hits the membrane 13. That is to say, FIG. 31 shows a statein which the swell of the membrane 13 is insufficient, in other words, astate in which the gap g between the membrane 13 and the top ring body11 is too small.

FIG. 32 is a diagram schematically showing a state after starting therelease following FIG. 33. When further pressurizing the area 133, themembrane 13 further swells and the gap g between the upper surface ofthe membrane 13 and the top ring body 11 further increases. In otherwords, the membrane 13 moves further downward. In this state, the fluidjetted from the release nozzles 802 hits near the boundary between thesubstrate W and the membrane 13. Therefore, the fluid flows into betweenthe substrate W and the membrane 13.

As described above, a state continues in which the fluid is jetted fromside into between the membrane 13 that swells to some extent and thesubstrate W, so that it is possible to effectively release the substrateW from the membrane 13. That is to say, FIG. 32 shows a state in whichthe swell of the membrane 13 is appropriate, in other words, a state inwhich the gap g between the membrane 13 and the top ring body 11 isappropriate.

However, it is not necessarily possible to continue the state of FIG.32.

FIG. 33 is a diagram schematically showing a state after starting therelease following FIG. 32. When further pressurizing the area 133, themembrane 13 further swells and the gap g between the upper surface ofthe membrane 13 and the top ring body 11 further increases. In otherwords, the membrane 13 moves further downward. In this state, the fluidjetted from the release nozzles 802 hits the membrane 13, but hardlyhits the substrate W. That is to say, FIG. 33 shows a state in which theswell of the membrane 13 is too large, in other words, a state in whichthe gap g between the membrane 13 and the top ring body 11 is too large.

As described above, to reliably release the substrate W, it is necessaryto control the swell of the membrane 13 (in other words, the gap gbetween the membrane 13 and the top ring body 11). Therefore, in thepresent embodiment, to maintain a state in which the swell of themembrane 13 is appropriate as shown in FIG. 32, the pressure control ofthe area 133 is performed as described below.

FIG. 34 is a cross-sectional view schematically showing a structure ofthe top ring 1 in the fifth embodiment. Different from FIG. 33, ameasurement value of the flow meter FS is inputted into the controller71. Then, the controller 71 controls the pressure adjustor 72, thevalves V1 to V9, and the pressure regulators R1 to R9 based on themeasurement value of the flow meter FS.

When releasing, the controller 71 opens the valve V10 to open the area131 to the atmosphere while opening the valve V1 to somewhat pressurizethe area 131. As described in the third embodiment, the flow volumemeasured by the flow meter FS corresponds to the size of the gap gbetween the membrane 13 and the top ring body 11. The size of the gap gcorresponds to the swell of the membrane 13. Therefore, the controller71 appropriately controls the pressure of the area 133 by monitoring theflow volume.

FIG. 35 is a flowchart showing an operation of the top ring 1 during therelease. FIG. 36 is a diagram schematically showing a flow volumemeasured by the flow meter FS during the release. The controller 71controls the pressure of the area 133 so that the flow volume is withina predetermined range between an upper limit threshold value and a lowerlimit threshold value by operating as described below. As shown in FIG.32, the fact that the flow volume is within a predetermined rangecorresponds to the fact that the swell of the membrane 13 isappropriate. In other words, a range of the flow volume where the swellof the membrane 13 is appropriate is set as the predetermined range.

First, the controller 71 starts pressurization of the adsorption area133 (step S21 in FIG. 35 and time point t20 in FIG. 36). Accordingly,the flow volume increases. However, the controller 71 continues thepressurization of the adsorption area 133 until the flow volume reachesthe upper limit threshold value (NO in step S22, and S21). Thepressurization is performed by continuously or intermittently supplyingair to the area 133. During this period, the membrane 13 graduallyswells, and accordingly the flow volume increases (see FIG. 36). After atime point t21 at which the flow volume reaches the lower limitthreshold value (that is, the swell of the membrane 13 becomesappropriate), it is possible to jet fluid from the release nozzles 802into between the substrate W and the membrane 13.

When the flow volume reaches the upper limit threshold value (time pointt22 and YES in step S22 in FIG. 35), the controller 71 determines thatthe swell of the membrane 13 is sufficient and stops the pressurizationof the adsorption area 133 (step S23). Specifically, the controller 71may stop air supply to the adsorption area 133, may close the valve V3,or may open the area 133 to the atmosphere. Alternatively, thecontroller 71 may depressurize the adsorption area 133.

When the pressurization of the adsorption area 133 is stopped, the swellof the membrane 13 decreases, and accordingly the flow volume maydecrease. Therefore, although the controller 71 stops the pressurizationof the adsorption area 133 until the flow volume reaches the lower limitthreshold value (NO in step S24, and S23), when the flow volume reachesthe lower limit threshold value (YES in step S24 and time point t23 inFIG. 36), the controller 71 determines that the swell of the membrane 13is insufficient and resumes the pressurization of the adsorption area133 (step S25).

By repeating the above operation, the flow volume is within apredetermined range, so that the swell of the membrane 13 becomesappropriate and it is possible to continue jetting fluid into betweenthe substrate W and the membrane 13 as shown in FIG. 32.

The release operation shown in FIG. 35 may be continued for apredetermined time or the release operation may be ended when a releasedetection sensor (not shown in the drawings) detects that the substrateW is released. The release detection sensor can be formed by, forexample, a light emitting portion and a light receiving portion whichare fixed to the retainer ring station 800.

As another method of estimating the swell of the membrane 13, it can beconsidered that the swell of the membrane 13 is estimated from anintegrated amount of air supplied to the adsorption area 133. However,the air not only flows into the adsorption area 133, but also flows intothe halfway flow path 143, a pipe of a rotary joint (not shown in thedrawings), and the like. Therefore, it is difficult to accuratelyestimate the swell of the membrane 13 from the integrated amount of air.

On the other hand, in the present embodiment, the flow volume of thedetermination area 131, that is, the volume of air flowing per unittime, is used. The flow volume corresponds to the size of the gap gbetween the membrane 13 and the top ring body 11, and the gap gcorresponds to the swell of the membrane 13. Therefore, it is possibleto accurately detect the swell of the membrane 13, so that it ispossible to accurately adjust the pressure of the adsorption area 133 soas to maintain an appropriate swell.

In FIGS. 28A to 33, an example in which the release nozzles 802 areattached to the retainer ring station 800 is shown. The retainer ringstation 800 does not move, so that the release nozzles 802 are alsofixed. As another example, when transferring the substrate W by using aso-called pusher instead of the retainer ring station 800, the releasenozzles may be attached to the pusher.

FIG. 37 is aside view schematically showing an operation in which thesubstrate W is released from the top ring 1 and transferred to a pusher160. The pusher 160 includes a top ring guide 161, a pusher stage 162,and release nozzles 802′ formed inside the top ring guide 161. Whenreleasing the substrate W, the pusher 160 moves up and approaches thetop ring 1. The other operations are the same as those in a case inwhich the retainer ring station 800 is used. When the pusher 160 isused, the release nozzles 802′ move along with the pusher 160.

Also in the fifth embodiment, a pressure gage may be installed in theflow path 141 or the flow path 150 and a pressure corresponding to theflow volume of the determination area 131 may be measured. In this case,the “flow volume” in FIG. 36 may be replaced with the “pressure”.

Sixth Embodiment

A sixth embodiment described below relates to a desired shape of themembrane 13.

FIG. 38 is a cross-sectional view of the top ring body 11 and themembrane 13 near the area 131. The dashed-dotted line in FIG. 38indicates the center of the top ring body 11 and the membrane 13. FIG.39 is a view of the membrane 13 near the area 131 as seen from above(from the top ring body 11). FIG. 40 is a view of the top ring body 11near an area 131 as seen from below (from the membrane 13).

As shown in FIGS. 38 and 39, a ring-shaped convex portion 131 a facingthe top ring body 11 is formed in a portion corresponding to the area131 on the upper surface of the membrane 13.

Further, as shown in FIGS. 38 and 40, a ring-shaped concave portion 11 ais formed in a portion corresponding to the area 131 in the top ringbody 11. A hole 21 a (first hole) of the top ring body 11, whichcommunicates with the flow path 141, is located outside the concaveportion 11 a. A hole 21 b (second hole) of the top ring body 11, whichcommunicates with the flow path 150, is located inside the concaveportion 11 a.

The convex portion 131 a of the membrane 13 is located at a positionfacing the concave portion 11 a of the top ring body 11. The convexportion 131 a and the concave portion 11 a can be engaged with eachother.

When the top ring 1 does not hold the substrate, there is a gap betweenthe convex portion 131 a of the membrane 13 and the concave portion 11 aof the top ring body 11. On the other hand, when the top ring 1 adsorbsand holds the substrate, the gap disappears or at least decreases. Thatis to say, the convex portion 131 a and the concave portion 11 a can becalled a seal portion that seals the area 131.

As shown in FIG. 40, the top ring body 11 is provided with a pluralityof grooves 11 b extending radially. Thereby, the pressure propagateseasily in the area 131, so that it is possible to equalize the pressure.In FIG. 40, the grooves 11 b are provided inside the concave portion 11a. However, the grooves 11 b may be provided outside the concave portion11 a. Or by providing the grooves 11 b in other areas such as the area132, the pressure easily propagates in the entire top ring.

The depth of the concave portion 11 a is set to equal to or deeper thanthat of the grooves 11 b and the height of the convex portion 131 a isset so that the convex portion 131 a can come into contact with theconcave portion 11 a, so that even when the grooves 11 b and the concaveportion 11 a interfere with each other, sealing is possible by theconcave portion 11 a and the convex portion 131 a.

FIG. 41 is a diagram showing a configuration example of the pressurecontrol apparatus 7 in a case in which the substrate adsorptiondetermination is performed by using the flow meter FS as described inthe third embodiment. In the same manner as in FIG. 14A, the flow paths141 and 150 are connected to the top ring body 11 through, for example,a rotary joint (not shown in the drawings). Different from FIG. 14A, thepressure control apparatus 7 includes a bypass line (a bypass flow path)151 and a valve 20. The bypass line 151 bypasses the flow path 141 andflow path 150. The valve V20 is provided on the bypass line 151. Thepressure control apparatus 7 can control the pressure of (for example,pressurize) the area 131 from the flow path 150 through the hole 21 b byopening the valve V20.

In the adsorption determination in the third embodiment described above,the determination area 131 is pressurized through the flow path 141 andis opened to the atmosphere through the flow path 150. Further, thedetermination area 131 is pressurized during the polishing. Thesepressurizations will be described.

FIG. 42 is a diagram for explaining the pressurization during theadsorption determination. As shown in FIG. 42, the valves V1 and V10 areopened and the valve V20 is closed. Thereby, in the same manner as inthe third embodiment, it is possible to pressurize the determinationarea 131 through the flow path 141 and open the determination area 131to the atmosphere through the flow path 150.

FIG. 43 is a diagram for explaining the pressurization while polishingthe substrate. As shown in FIG. 43, the valves V1 and V20 are opened andthe valve V10 is closed. Thereby, the area 131 is pressurized from boththe flow paths 141 and 150 at the same time. Specifically, it ispossible to pressurize the outside of the ring-shaped portion sealed bythe concave portion 11 a and the convex portion 131 a from the flow path141. Further, it is possible to pressurize the inside of the ring-shapedportion sealed by the concave portion 11 a and the convex portion 131 afrom the flow path 150. In particular, the grooves 11 b are provided asshown in FIG. 40, so that the pressure is propagated to the entireinside of the sealed ring-shaped portion.

Further, a pressurized pressure during the adsorption determination isapplied from the outside of the sealed ring-shaped portion and theinside of the sealed ring-shaped portion is opened to the atmosphere.Therefore, a central portion of the substrate W is not pressurized, sothat the substrate W is prevented from being deformed and stress issmall.

The top ring body 11 and the membrane 13 as described above are used, sothat it is possible to more accurately perform the adsorptiondetermination described in the third embodiment.

FIG. 44 is a diagram schematically showing cross sections of thesubstrate W, the membrane 13, and the top ring body 11 when theadsorption succeeds. FIG. 44 corresponds to FIG. 20. As known from FIG.44, when the substrate adsorption succeeds, the convex portion 131 a ofthe membrane 13 engages with the concave portion 11 a of the top ringbody 11 and the gap between them almost disappears. As a result, theflow volume measured by the flow meter FS becomes very small and theaccuracy of the determination improves.

As described above, in the sixth embodiment, the convex portion 131 a isprovided to the membrane 13 and the concave portion 11 a is provided tothe top ring body 11. Therefore, the convex portion 131 a and theconcave portion 11 a form a seal portion and the membrane 13 is closelyattached to the top ring body 11 when the substrate is adsorbed.Therefore, a difference between the flow volume when the substrateadsorption succeeds and the flow volume when the substrate adsorptionfails is large, so that the accuracy of the substrate adsorptiondetermination improves.

It is desirable to be able to realize a state that is completely sealedby the convex portion 131 a and the concave portion 11 a. However, asubstantially sealed state may be formed by a certain portion of themembrane 13 and a certain portion of the top ring body 11.

In the present embodiment, the convex portion 131 a is provided to themembrane 13 and the concave portion 11 a is provided to the top ringbody 11. However, as the seal portion, a concave portion 131 b may beprovided to the membrane 13 and a convex portion 11 c may be provided tothe top ring body 11 (see FIG. 45). When an area other than the area 131is used as the determination area, a concave portion and/or a convexportion may be provided to the determination area as a seal portion.

As described in the fourth embodiment, when the substrate adsorptiondetermination is performed by using the pressure gauge PS, the pressuregauge PS may be is installed in the flow path 141 in the same manner asin FIG. 22.

The above embodiments are described in order for a person with anordinary skill in the art to which the present invention pertains toimplement the present invention. Various modified examples of the aboveembodiments can be naturally made by those skilled in the art and thetechnical idea of the present invention can be applied to otherembodiments. A plurality of embodiments can be arbitrarily combined.Therefore, the present invention is not limited to the describedembodiments and should have the greatest range according to thetechnical ideas defined by claims.

1. A method to adsorb a substrate to a top ring comprising a top ringbody and an elastic film under the top ring body, the method comprising:vacuuming at least one area among a plurality of areas formedconcentrically between a top face of the elastic film and the top ringbody under a state where a bottom face of the substrate is supported bya support member and a top face of the substrate contacts a bottom faceof the elastic film; measuring a flow volume of gas in an area locatedoutside one or more areas to be vacuumed; determining whether thesubstrate is adsorbed to the top ring based on the flow volume of thegas; and after it is determined that the substrate is adsorbed to thetop ring, separating the elastic film to which the substrate is adsorbedfrom the support member.
 2. The method according to claim 1 furthercomprising measuring pressure of at least one area among the one or moreareas to be vacuumed after vacuuming at least one area among theplurality of areas, wherein whether the substrate is absorbed isdetermined taking into consideration the flow volume of the gas and thepressure of at least one area among the one or more areas to bevacuumed.
 3. The method according to claim 1 further comprising:pressuring at least one area among the plurality of areas; andcontacting the top face of the substrate with the bottom face of theelastic film, wherein vacuuming at least one area among the plurality ofareas is performed thereafter.
 4. The method according to claim 3,wherein upon pressuring at least one area, at least one of the areas tobe vacuumed is pressured.
 5. The method according to claim 1, wherein anarea located outside the areas to be vacuumed is not pressured when thetop face of the substrate contacts the bottom face of the elastic film.6. The method according to claim 1, wherein the support member is atransfer mechanism configured to transfer the substrate to the top ring.7. The method according to claim 1, wherein the support member is apolishing table configured to polish the substrate holed by the topring.
 8. A substrate holding apparatus comprising: a top ring body; anelastic film under the top ring body, a plurality of areas beingconcentrically formed between a top face of the elastic film and the topring body; a pressure controller configured to vacuum at least one areaamong the plurality of areas under a state where atop face of asubstrate whose bottom face is supported by a support member contacts abottom face of the elastic film; a flow meter configured to measure aflow volume of gas in an area located outside one or more areas to bevacuumed; and a determiner configured to determine whether the substrateis adsorbed to the top ring based on the flow volume of the gas.
 9. Theapparatus according to claim 8, wherein a flow path on which the flowmeter is provided is connected to the area located outside the one ormore areas to be vacuumed, and the flow path is not branched betweensaid area and the flow meter.
 10. The apparatus according to claim 8,wherein no holes are formed on the elastic film at a position where theplurality of areas are formed.
 11. A substrate polishing apparatuscomprising: the substrate holding apparatus according to claim 8; atransfer mechanism configured to transfer the substrate to the substrateholding apparatus; and a polishing table configured to polish thesubstrate held by the substrate holding apparatus.
 12. A substrateholding apparatus comprising: a top ring body; an elastic filmcomprising a first face and a second face opposite the first face, aplurality of areas being formed between the first face and the top ringbody, the second face being capable of holding a substrate; a first linecommunicating with a first area among the plurality of areas and capableof pressuring the first area; a second line communicating with the firstarea and capable of exhausting the first area; a measurement instrumentwhose measurement value varies based on a flow volume of the first area;a third line communicating with a second area among the plurality ofareas and different from the first area, the third line being capable ofpressuring or depressurizing the second area.
 13. The apparatusaccording to claim 12, wherein the measurement instrument is a flowmeter capable of measuring a flow volume of the second line.
 14. Theapparatus according to claim 12, wherein the measurement instrument is apressure gauge capable of measuring a pressure of the first line of thesecond line.
 15. The apparatus according to claim 12 further comprisinga determiner configured to determine whether the substrate is adsorbedto the second face based on the measurement value.
 16. The apparatusaccording to claim 15 further comprising a controller configured to,when the substrate is adsorbed to the second face, depressurize thesecond area through the third line and pressure the first area throughthe first line and make a fluid through the second line; wherein thedeterminer determines whether the substrate is adsorbed to the secondface based on the measurement value when the substrate is adsorbed tothe second face.
 17. The apparatus according to claim 16, wherein thedeterminer determines whether the substrate is adsorbed to the secondface based on the measurement value measured by the measurementinstrument after a first time from a start of depressurizing the secondarea.
 18. The apparatus according to claim 12 further comprising acontroller configured to control a pressure of the second area throughthe third line based on the measurement value.
 19. The apparatusaccording to claim 18, wherein the controller controls the pressure ofthe second area so that the measurement value falls within a firstrange.
 20. The apparatus according to claim 18, wherein the controller,when the substrate held by the second face is released, pressures thefirst area through the first line and make a fluid into the first areathrough the second line, and controls the second area through the thirdline based on the measurement value.
 21. The apparatus according toclaim 18, wherein the controller controls the pressure of the secondarea so that a fluid is injected to a first position from a releasenozzle.
 22. The apparatus according to claim 21, wherein the firstposition is between the second face and the hold substrate.
 23. Theapparatus according to claim 12, wherein no holes are formed on theelastic film.
 24. The apparatus according to claim 12, wherein thesecond area is not adjacent to the first area.
 25. The apparatusaccording to claim 12 further comprising a retainer ring at an outercircumference of the elastic film.
 26. The apparatus according to claim25, wherein the retainer ring comprises an inner ring and an outer ringoutside the inner ring.
 27. A substrate polishing apparatus comprising:the substrate holding apparatus according to claim 12; and a polishingtable configured to polish the substrate held by the substrate holdingapparatus.
 28. A substrate adsorption determination method for asubstrate holding apparatus, the method comprising: depressurizing asecond area formed between a top ring body and a first face of anelastic film in the substrate holding apparatus, pressuring a first areaformed between the top ring body and the first face of the elastic filmdifferent from the second area and making a fluid through a second linecommunicating with the first area; and determining whether the substrateis adsorbed to a second face of the elastic film opposite the first facebased on a measurement value varying according to a flow volume of thefirst area.
 29. A pressure control method for a substrate holdingapparatus, the method comprising: pressurizing a first area formedbetween a top ring body and a first face of an elastic film in thesubstrate holding apparatus, and making a fluid through a second linecommunicating with the first area; and controlling a second area formedbetween the top ring body and the first face of the elastic filmdifferent from the first area based on a measurement value varyingaccording to a flow volume of the first area.
 30. An elastic film usedwith a top ring body provided with a first hole at an outside of a firstportion and a second hole at an inside of the first portion to configurea substrate holding apparatus, the elastic film comprising: a first faceprovided with a second portion capable of being engaged with the firstportion, a plurality of areas being formed between the first face andthe top ring body; and a second face opposite the first face, the secondface being capable of holding a substrate.
 31. The elastic filmaccording to claim 30, wherein the first portion is a concave portionand the second portion is a convex portion, or the first portion is aconvex portion and the second portion is a concave portion.
 32. Asubstrate holding apparatus comprising: a top ring body provided with afirst hole at an outside of a first portion and a second hole at aninside of the first portion; an elastic film comprising: a first faceprovided with a second portion capable of being engaged with the firstportion, a plurality of areas being formed between the first face andthe top ring body; and a second face opposite the first face, the secondface being capable of holding a substrate; a first line being capable ofpressuring a first area through the first hole positioned at the firstarea among the plurality of areas; a second line capable ofdepressurizing the first are through the second hole positioned at thefirst area; a measurement instrument whose measurement value variesbased on a flow volume of the first area; and a third line communicatingwith a second area among the plurality of areas and different from thefirst area, the third line being capable of pressuring or depressurizingthe second area.
 33. The substrate holding apparatus according to claim32, wherein a radially spreading groove is provided at a portion of thetop ring body corresponding to the first area.
 34. The substrate holdingapparatus according to claim 32 further comprising: a bypass lineconfigured to connect the first line with the second line; and a valveprovided on the bypass line.